Rotary pump with seizure preventing means



nvemor Ctlorllcgs 2 Sheets-Sheet l April 19, 1949. R. w. FERNSTRUM ROTARY PUMP WITH SEIZURE PREVENTING MEANS Filed Sept. 2, 1944 April 19, 1949. R. w. FERNSTRUM ROTARY PUMP WITH SEIZURE PREVENTING MEANS Filed Sept. 2, 1944 2 Sheets-Sheet 2 lnvcntor Gttorucp Patented Apr. 19, 1949 ROTARY PUMP WITH SEIZURE PREVENTING MEANS Robert W. Fernstrnm, Detroit, Mich., assignor to Gray Marine Motor Company, Detroit, Mich., a

corporation of Michigan Application September 2, 1944, Serial No. 552,440

The present invention relates to improvements in fluid pumps, and more particularly to a fluid damage to the impellers of the pump should the intake pipe of the marine engine circulatory cooling system be raised or elevated out of the water for any reason whatsoever.

Another object of the invention is to provide a rotary pump for the liquid circulatory cooling system of a marine engine in which flexible and compressible impellers are employed and in which a bypass from the reservoir is provided for maintaining said impellers lubricated by a small amount of liquid trapped in the pump casing so that when said marine engine and pump are operated the impellers will not be damaged when the intake of said pump is not in communication with a supply of cooling liquid.

Another object of the invention is to provide a pump for the liquid circulatory cooling system of marine engines and the like in which the pump casing is provided with a reservoir communicating with the pump chamberthrough a lateral port adjacent the exhaust port of the pump so that liquid will be pumped into said reservoir chamber and will pass from said reservoir to the impellers of the pump when the intake of the pump is out of communication with the circulatory cooling liquid.

Another object of theinvention is to provide a pump of the above-mentioned character in which the impellers are formed of synthetic rubber interengaging gear members suchas buna or butadiene to permit the passage of particles of sand and gravel therebetween without causing damage and breakage to said impellers when the marine craft is temporarily beached or driven through water near sandy beaches so as to expose the cooling system i'ntakc to water contaminated with sand, shell particles and gravel.

Another object of the invention is to provide a liquid pump for circulatory cooling systems of marine engines in which the pump may be conveniently located and afixed to the engine casting and drivingly connected to the timing gearing thereof so that the outlet pipe of the pump may be inclined to the water jacket intake of said engine whereby condensation in said outlet pipe will drain to the reservoir of said pump and assist in maintaining a liquid level therein to 3 Claims. (Cl. 103-126) lubricate the impellers and prevent damage and excessive wear thereto.

Another object of the invention is to provide a liquid pump for circulating cooling liquid through the water jacket of marine engines in which the synthetic rubber impellers will be automatically lubricated to prevent excessive wear should the cooling system inlet pipe of the marine craft be raised out of the water, with the engine in operation or the engine operated with the cooling system inlet pipe in communication with the atmosphere.

Another object of the invention is to provide a circulating pump for the cooling system of a marine engine in which the pump casing is provided with a reservoir chamber for feeding liquid to the pump impellers so as to initiate liquid flow therethrough when the pump is put into operation and thereby prime the pump without resort.- ing to external priming means.

Other objects and advantages of the invention will become apparent during the course of the following description of the accompanying drawings, wherein:

Figure 1 is a top plan view of the pump structure embodying the invention, illustrating portions thereof broken away to show various structural details thereof;

Figure 2 is a vertical cross sectional view of the pump reservoir'taken on line 22 of Figure 1, looking in the direction of the arrows to illustrate the relative position of said reservoir with respect to the pump impellers;

Figure 3 is a vertical cross sectional view taken on line 3-3 of Figure 2 looking in the direction of the arrows and illustrating the manner in which the reservoir is communicated with the pump chamber through a passageway offset from said reservoir chamber;

Figure 4 is a longitudinal cross-sectional view taken on line 4-4 of Figure 1 looking in the direction of the arrows illustrating the reservoir chamber in detail and showing the interengaging pump impellers;

Figure 5 is a horizontal cross sectional view taken on line 5-5 of Figure 2 looking in the direction of the arrows illustrating the manner in which the interengaging impellers are drivingly geared together and further, showing various details of construction of the pump casing and drive gearing for said impellers; and

Figure 6 is a side elevational view of the liquid pump illustrating diagrammatically the manner inwhich said pump is coupled with the inlet and the pump 5 with the inlet l extending through.

the hull of the marine craft as at I I so as to pump sea water through the cooling jacket of the engine 8 to thereby cool the engine during operation. The water jacket of the engine 8 is provided with an exhaust pipe l2 which may project through the hull of the marine craft above the water line thereof so as to discharge the cooling liquid after being circulated through the engine cooling jacket.

Generally, the intake pipe I0 is provided on its submerged end with a scoop positioned adjacent the propeller and rudder assembly so that as the boat is being propelled through the water, the water will be forced through the inlet pipe ID to the pump and then circulated through the cooling jacket of the engine. In constructions of this type, considerable sand and gravel is collected and passed through the pump 5 when cruising near beaches and it is therefore necessary to employ pump impellers which will permit the passage of said sand and gravel particles without damaging or breaking the impeller parts. In the present structure, deformable impellers are provided so as to pass said sand particleswithout damaging the impellers or pump casing or other parts of the pump construction.

The construction shown in the drawings is adapted to be fastened or afiixed and supported by the marine engine 8 and the section 6 of the pump casing is shaped to provide a flanged portion I3 and a rib portion |4 adapted to interfit with a recess and opening in the engine casing so that the section 6 may be bolted thereto by suitable machine screws or the like being passed through apertures in the flange I3. Also, the section 6 comprises a front wall l5 and a partition wall l6 adjacent the front and back of the oval-shaped casting or section 6. Formed in the front wall I5 is a pair of annular bosses l1 and I8 surrounding openings I9 and 28 respectively which are adapted to form bearing openings for a pair of rotary,

pump shafts 2| and 22 respectively. The bearing bores 20 are enlarged as at 23 and 24 for receiving a quantity of sealing material or packing 25. Gland nuts 26 and 21 are anchored in place by means of bolts or the like as at29 and 30 so as to clamp the packing 25 about the shafts 2| and 22 and prevent the escape or passage of liquid between thesections 6 and I of the pump casing.

The partition wall I6 is provided with a pair of openings or bores 3| and 32 in axial alignment with the openings I9 and 20 to permit the passage of the shafts 2| and 22, and mounted in said openings or bores 3| and 32 are outer race members 33 and 34 of anti-friction bearings (Figure 5) including a series of ball-bearings 35 and 36 interposed between the race members 33 and 34 and shafts 2| and 22. The inner race members 31 and 38 are secured to reduced portions of the shafts 2| and 22 respectively and said shafts are extended to project a slight distance on the opposite side of the partition wall IS.

The shaft 2| has affixed to the inner end thereof a gear 39 by means of a key 40 and keyway 4| and said gear is held in place by a nut 42 threaded on a threaded portion of the shaft 2| as indicated in Figure 5. Similarly, a spur gear 43 is affixed to the inner ends of the rotary shaft 22 by means of a key 44 and keyway 45 and is likewise held in place by a nut 46 threaded on the screw-threaded end of said shaft. The spur gear 43 is slightly wider than the spur gear 39.50 that a portion of the teeth thereof will project beyond the ovalshaped rib I4 and extend into the engine casting of the marine motor 8. The gear 43 is adapted to be driven by an internal gear 41 carried by the free end 48 of the cam shaft of the engine. The'spur gear 43 is so positioned as to interfit with the teeth of the internal gear 41 and thereby permit removal of the section 6 of the pump casing to facilitate repair of the gears and various other parts of the pump structure. Also, it is noted that the spur gears 39 and 43 are positioned to be in driving engagement with each other whereby the shafts 2| and 22 will rotate in unison in opposite directions.

The pump casing section is of general ovate shape and includes an elliptical wall portion 50 having an end wall 5| and said section I is further shaped to provide semi-circular recesses 52 and 53 to form cylinders for a pair of interengaging impellers 54 formed of synthetic rubber such as buna or butadiene. The impellers 54 are provided with bronze sleeves or bushings 55 which are keyed as at 56 to their respective shafts 2| and 22. Interposed between the sections 6 and 1 is an end wall plate "21 so as to close the open end of the pump casing and said sections are held together by clamping bolts 58 having their threaded ends 59 threaded in suitable bosses 6|! in the section 6.

Offset from the pump casing and formed integral therewithjs a collection chamber or reservoir 62 which is adapted to collect and store in reserve a quantity of liquid for the purpose of lubricating the impellers 54 and preventing deterioration thereof in the event that the pump is operated when the intake tube I8 is out of the water or when the marine craft is temporarily dry-docked so as to prevent injury to the impellers by excessive wear. The chamber 62 includes a side wall portion 63, bottom wall portion 64,- and end wall portion 65. A rear wall 68 integrates the end wall portion with the bottom wall portion 64 to thereby form a closed reservoir chamber in communication with the impeller cavities 53 through an opening or passageway 65 forming an exhaust port 61 for the pump so that the fluid passing from the pump to the chamber will be normally under pressure. An intake opening or port 68 is formed in the pump casing section and is adapted to communicate with the intake pipe I0 (Figure 6) in such a manner as to draw sea water th'erethrough when the pump impellers 54 are rotated in unison.' Threaded bores 69 are formed in the pump casing section to facilitate the bolting of the flange 10 of the intake pipe thereto by means of bolts or the like The reservoir chamber 62 is provided with a top wall portion 12 which is shaped to receive a pipe flange and said wall is provided with a port 13 communicating the interior of the chamber 62 with the intake pipe 9 of the water-cooling jacket 8. The pipe flange 14 of the intake pipe 9 is bolted in place by machine screws or the like 15 being received in threaded openings 16.; in the 'top wall 12. The structure above described provides a reservoir chamber on the exhaust side of the pump and forms a trap having a relatively large volumetric area for containing a large or offset extension 18 integrated with the pump section I and reservoir chamber 82 and provided with a passageway 19 having one end communicating with the reservoir chamber through a laterally extending port 88 and the other end communicating with the pump chamber througha laterally extending port' 8|. The passageway 19 includes a vertical passageway portion 82which extends upwardly between bearing bosses 83 and 84 for the ends of their respective shafts 2| and 22 and the lower end of said vertical passageway 82 is in communication with the pump chamber through the port 8| which is formed as shown in Figure 2 between the impeller cavities 52 and 53 at a point slightly below the axis or the shafts 2| and 22. The passageway 18 is slightly curved at the other end and terminates in the discharge port 88 located at the uppermost portion of the side wall 88 of said reservoir chamber 82. As shown clearly in Figures 1 to 3 inclusive, the offset extension 18 is formed integral with the front wall 83 of the pump chamber and reservoir and the port 8| is formed integral with the front wall 83 communicating with the interior of the reservoir chamber 82 through the fluid passageway 19. The division plate 21 is adapted to close the rear wall of the pump chamber and as shown in Figure 5, the rear wall of the reservoir chamber is integrated with the pump chamber so that when the bolts 58 are removed, the entire pump chamber and reservoir chamber comprising the pump section I may be removed as a unit. When removed, the section I is simply slid horizontally so as to be removed from the shafts 2| and 22, shown in Figures 1 to 3 inclusive.

Closure plugs 84a are fitted in the ends of the tubular bearing bosses 83 and 84 to close the same against the entrance of foreign matter, and a cleanout plug 85 is provided in the reservoir chamber 82 to facilitate the removal of foreign matter therefrom.

In operation, the impellers 54 are rotated in unison by means of the spur gears 39 and 43 when the pump casing 5 is assembled on a marine engine in the manner as set forth. When the impellers are rotated, sea water is drawn upwardly through the intake pipe l0 and forced .through the circulatory system of the engine cooling jacket 8 by being passed through the reservoir chamber 82 and pipe 9. In the event that the marine craft is raised out of the water when the same is beached or in dry dock and the motor 8 is operated, the quantity of water or liquid trapped in the chamber 82 .will be drained through the port 88, passageway 19 and port 8| and thence again,

to the interior of the reservoir chamber 82. The water trapped in chamber 62 thus flows to the synthetic rubber impellers 54 and thereby lubricates said impellers. The port 8| and passageway 19 permits air from said pump casing to be forced into the uppermost portion of the reservoir casing, thereby placing the liquid therein under a slight pressure head. The passageway or port 8| will not affect the normal operation charge portion of the pump. and will enable the pump to be operated for a considerable length of time when the intake pipe llils not submerged without causing the impellers 84 to be burnt and scorched through excessive frictional heat. The

circulating passageway 18 prevents the impellers 54 from blowing the trapped liquid out of the chamber 82 so as to permit feeding of said impellers with a smallamount of water suflicient to lubricate the impellers and thereby prevent damage thereto.

The reservoir 82 may also be used in pumps having bronze or brass impellers with similar results. And while water is not a very good lubri'cant for metal and metal impellers such as bronze or brass, the reservoir 82 will feed said impeller with a slight amount of water to pre- ,yent excessive damage in the event the engine and pump are operated while the intake is out of communication with the source of liquid and exposed to the atmosphere.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred embodiment of the same and that various changes may be made in the shape, size and arrangement of parts without departing from the spirit of the invention or the scope of the subjoined claims.

What I claim is:

1. A fluid pump comprising a casing having a pump chamber provided with inlet and exhaust ports and intake and exhaust passages communicating with said inlet and exhaust ports, a gear pump housed in said pump chamber, said exhaust passage having an outlet and being return bent and conducting the exhaust fluid in a direction opposite to the flow of fluid through said intake passage and said pump chamber, and said casing provided with a separate return passage ofiset to one side of said intake and exhaust passages, said return passage communicating at one end with said exhaust passage adjacent the outlet and at the other end with said pump chamber immediately adjacent to said pump chamber exhaust port wherebyto provide a generally downwardly sloping passage permitting -the fiuid in said exhaust passage to flow by gravity to wet said pumping gears.

2. A fluid pump comprising a casing having a pump chamber provided with inlet and exhaust ports and intake and exhaust passages communicating with said inlet and exhaust ports, a gear pump housed in said pump chamber, said exhaust ately adjacent to said pump chamber exhaust portpassage having an outlet and being return bent and conducting the exhaust fluid in a direction opposite to the flow of fluid through said intake passage andsaid pump chamber, and said casing provided with a separate return passage offset to one side of said intake and exhaust passages, said return passage communicating at one end with said exhaust passage adjacent the outlet and at the other end with said pump chamber immediwhereby to provide a generally downwardly sloping passage permitting the fluid in said exhaust passage to flow bygravity to wet said pumping of the pump, because in normal operation the sea gears, said exhaust passage comprising an enlarged intermediate portion whereby to provide a relatively large reservoir serving to provide a maximum of fluid for drawing through said return passage.

3. A fluid pump comprising a casing having a pump chamber provided with inlet and exhaust ports and intake and exhaust passages communicating with said inlet and exhaust ports, a gear pump housed in said pump chamber, said exhaust passage having an outlet and being return bent and conducting the exhaust fluid in a direction opposite to the fiow of fluid through said intake passage and said pump chamber, and said casing provided with a separate return passage offset to one side of said intake and exhaust passages, said return passage communicating at one end with said exhaust passage adjacent the outlet and at the other end with said pump chamber immediately adjacent to said pump chamber exhaust port whereby to provide a generally downwardly sloping passage permitting the fluid in said exhaust passage to flow by gravity to wet said pumping gears, said return passage emptying into said pump chamber through a side wall so that the fluid will flow across the gear teeth on its way to said pump chamber exhaust port.

ROBERT W. FERNSTRUM.

8 REFERENCES CITED The following references are of record inthe file of this patent:

UNITED STATES PATENTS 

